The present invention relates to an explosion-proof electrical apparatus and in particular to a feedthrough fitting assembly for use in such an apparatus, as well as a method for installing same.
In certain electrical apparatus, it is necessary to connect electrical terminals to arc-producing electrical devices such as circuit breakers, switches, relays and meters for example, in a manner isolating the arcs from the surrounding environment. This is conventionally accomplished by positioning the arc-producing devices within respective explosion-proof (flame-proof) enclosures, and running the electrical conductors from one device to another through an explosion-proof fitting mounted on adjacently disposed walls of the enclosures. The fittings contain sealing compound which surrounds the conductors to isolate the surrounding environment from the interiors of the enclosures.
It is desirable to ensure that the fittings are explosion-proof so that the environment surrounding the enclosures is assuredly protected against sparks which might occur within the enclosures. It is also desirable to ensure that each of the enclosures is isolated from any sparks produced in the other enclosure. Up until now, fittings which fulfill that goal have been difficult to install and/or remove.